The invention relates to supplying electric power to electrical devices carried by the rotor of an aircraft engine.
The field of application of the invention is more particularly that of aircraft engines, especially gas turbine engines. In particular, the invention relates to an unducted fan engine, comprising two counter-rotating rotors, each carrying adjustable blades.
There are engines in which the rotor bears adjustable blades. The orientation of the blades can be modified during flight to enable optimised operation of the engine. This is especially the case of engines of the unducted fan engine type (Open Rotor), comprising two counter-rotating rotors, each carrying adjustable blades. For example, the orientation of the blades can be modified by an electromechanical actuator supported by the rotor.
Electric power must be transmitted to the rotor to feed such an actuator. For this, a brush device is typically used. However, brush devices are generally less reliable and subject to rapid wear. They therefore need regular maintenance. Also, they are generally heavy and bulky and can raise compatibility problems with surrounding oils.
To solve these problems, document FR 2 712 250 proposes using an electric engine, the stator of which is fixed and the rotor of which has no electrical link to the stator and is attached to a toothed wheel connected mechanically to the blades to be oriented. This solution therefore imposes a mechanical link between the electric engine and the blades. The fixed part of the electric engine therefore cannot be positioned freely, which involves design restrictions. Also, no electric power is available at the rotor level to feed electrical devices. The same document therefore also proposes using a rotating transformer for feeding a lock.
When the power to be transmitted is high, a rotating transformer is generally a heavy and bulky device. Also, it is necessary to feed it from a source having a power which corresponds to the power required at the rotor level. A power converter and a power source dimensioned for high power are necessary.